A method of this general kind is known from U.S. Pat. No. 4,248,290 (Hermes). According to this method, a closed-loop control arrangement is used to avoid impact damage when newly-produced molds are joined to a string of previously produced molds, and/or to control the dimensions of the molds in the-direction of conveying said string.
When producing casting molds or mold parts according to this known method, problems may arise due to variations in the hardness of the produced molds or mold parts, depending on the degree of compaction, with which the compacting operation is carried out. In many cases, these variations are not detected at a sufficiently early stage to make it possible to prevent them from causing severe problems.
Thus, the molds or mold parts may be too hard and dense, thus partly making it difficult to separate the molds from the castings, partly making it difficult for, gases produced during the casting operation to escape, thus causing gas porosities in the castings.
On the other hand, the molds or mold parts may be too brittle or soft, in which case they will be unable to withstand the impact of the molten casting metal being poured into the pouring cup.